Gastro-esophageal reflux disease (GERD) is a common problem and is expensive to manage in both primary and secondary care settings. This condition results from exposure of esophageal mucosa to gastric acid and bile as the gastro-duodenal content refluxes from the stomach into the esophagus. The acid and bile damages the esophageal mucosa resulting in heartburn, ulcers, bleeding, and scarring, and long term complications such as Barrett's esophagus (pre-cancerous esophageal lining) and adeno-cancer of the esophagus. Nocturnal GERD is also known as night time GERD or supine GERD. More than half of patients with GERD also experience nocturnal GERD, which is associated with adverse sleep parameters, and may be diagnosed where a patient has reflux symptoms associated with sleep disturbances, nocturnal arousals, and early morning awakenings.
Although the frequency of reflux episodes decreases during sleep, many of the physiologic changes that occur with sleep favor development of severe esophagitis. These changes include (1) increased acid secretion that can also be seen as “nocturnal acid breakthrough” in GERD patients on proton pump inhibitor therapy; (2) a marked decrease in esophageal acid clearance with enhanced proximal migration owing to loss of gravitational effects in the supine position, decreased frequency of swallowing and therefore of primary peristalsis, decreased saliva production, or decreased perception of heartburn; and (3) changes in the gastric slow-wave electrical activity that could predispose a patient to decreased gastric emptying. Other factors such as sleep apnea and its relationship to obesity are also linked to GERD. The mechanism for this relationship may relate to apnea-related changes in intra-thoracic pressure, or to obesity-related factors such as increased intra-abdominal pressure and hiatus hernia.
Lifestyle advice and antacid therapy are advocated as first line treatment for the disease. However, since most patients with moderate to severe cases of nocturnal GERD do not respond adequately to these first-line measures and need further treatment, other alternatives including pharmacological, endoscopic, and surgical treatments are employed.
The most commonly employed pharmacological treatment is daily use of H2 receptor antagonists (H2RAs) or proton-pump inhibitors (PPIs) for acid suppression. Since gastro-esophageal reflux disease usually relapses once drug therapy is discontinued, most patients with the disease, therefore, need long-term drug therapy. However, daily use of PPIs or H2RAs is not universally effective in the relief of nocturnal GERD symptoms or as maintenance therapy. Additionally, not all patients are comfortable with the concept of having to take daily or intermittent medication for the rest of their lives and many are interested in nonpharmacological options for managing their reflux disease.
Therefore, there is still a need for a safe and effective method of treatment that can help alleviate symptoms of nocturnal GERD in the long term, without adversely affecting the quality of life of the patients. In particular, there is a need for simple, efficient nocturnal GERD device and treatment methods that do not inhibit a patient from swallowing and do not rely on an instantaneous response from the patient's LES to avoid episodes of acid reflux. There is a need for treatment protocols and devices which are programmed to implement such protocols, which can be easily programmed and do not require complex physiologic sensing mechanisms in order to operate effectively and safely. Moreover, there is not only a need for better devices in stimulation based therapies, but there is also a need for a safe and minimally invasive method and system that enables easy and expeditious deployment of such devices at any desired location in the body.
It is further desirable to have a system for the treatment of nocturnal GERD which includes a stimulator and an optional sensor adapted to be placed in a patient's LES tissue.
It is further desirable to have a system for the treatment of nocturnal GERD which includes an active implantable medical device (AIMD) and temporary sensor adapted to be placed in a patient's GI lumen where the sensors are designed to naturally dissolve or pass out through the lumen and the AIMD is adapted to dynamically acquire, process, measure the quality of, and use sensed data only when the sensor is present.
It is further desirable to have a system for the temporary treatment of nocturnal GERD which includes an AIMD, which is adapted to be placed in a patient's GI lumen, designed to naturally dissolve or pass out through the lumen, and is adapted to deliver electrical stimulation to tissue at or in the vicinity of the LES. Such temporary stimulation scheme can additionally be used for pre-screening of patients likely to benefit from permanent stimulation.
It would further be desirable for the stimulator to use periodic or occasional sensing data to improve the treatment of nocturnal GERD by dynamically detecting when a sensor is present, determining when a sensor is transmitting, or capable of transmitting, data, and processing the sensed data using an application having a special mode which opportunistically uses the sensed data to change stimulation parameters.
It is also desirable to automate the setting or calibration of some or all device parameters in order to reduce the need for medical follow-up visits, reduce burdens on healthcare providers and patients, decrease the rate of programming mistakes, and improve outcomes, thereby improving the treatment of nocturnal GERD.